AAMC FL 1 FULL REVIEW- Chem/Phys correctly answered 2023

AAMC FL 1 FULL REVIEW- Chem/Phys correctly answered 2023In the chromatography of the reaction mixture, water absorbed on cellulose functioned as the stationary phase. What was the principal factor determining the migration of individual components in the sample? A.Hydrogen bonding B.Solute concentration C.Stationary phase concentration D.Thickness of paper - correct answer B and D are dumb options. Knock them out. hydrogen bonding to the stationary phase will determine the relative rate of migration of the various components in the sample. When thinking migration, think bonding. If it bonds super well, it isn't going to move very far. What assumption is being made if scientists conclude that aspartic acid was formed by the prebiological synthesis in the passage? A.Aspartic acid is unstable at temperatures below 150°C. B.All of the malic acid underwent the dehydration reaction to form fumaric/maleic acid. C.Compound A and cyanide were available on primitive Earth. D.The reaction between ammonia and fumaric acid was catalyzed by the presence of water. - correct answer POE: D- is wrong. water is not a catalyst B- some of the magic acid was turned to aspartic acid in the next equation. WRONG. A- the 150 degrees comes into play when the scientists are doing the actual experiment, NOT the synthesis. C- passage has right before the figure of the reaction: "scientists have studied the production of amino acids under conditions that simulate those of primitive Earth." ^^^^this indicates that C is the right answer. According to the developed chromatography plate shown below, what is the approximate Rf value of aspartic acid? - correct answer Rf: distance travelled by analyze/distance traveled by solvent. 2/10--- 0.2 Which of the following statements does NOT correctly describe the dehydration of malic acid to fumaric acid and maleic acid? A.The reaction occurs most readily with tertiary alcohols. B.The reaction involves the loss of a water molecule. C.The reaction has a carbocation intermediate. D.The reaction is stereospecific. - correct answer NOT is the key word. DEHYDRATION involves: -loss of a water molecule (cross b out) -it does have a carbocation (sn1) -and does like tert substitutions (snl) D is wrong. Two products are made, therefore it is not stereospecific. What type of functional group is formed when aspartic acid reacts with another amino acid to form a peptide bond? A.An amine group B.An aldehyde group C.An amide group D.A carboxyl group - correct answer C. amide is the other end of the peptide bond! peptide bond= carboxyl group reacts with amine, making a c=o next to an N which is an amide If 2-pentanol replaces 1-pentanol in the reaction shown in Figure 3, the rate of substitution is less because: A.the C-O bond in 2-pentanol is stronger than the C-O bond in 1-pentanol. B.there is a competing elimination reaction that slows the rate of substitution. C.there is more steric hindrance at the oxygen atom in 2-pentanol than in 1-pentanol, making protonation less likely. D.there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of 1-pentanol. - correct answer Figure 3 shows an SN2 reaction. You know that SN2 reactions hate steric hinderance. It literally will not go with a tertiary one, but is hella slow with a secondary one. The steric hinderance is not at the oxygen. It's talking about all the other crap. What's important is the Halide being able to attack the carbocation intermediate, which is made more difficult by hinderance from the extra alkyl groups since it's further down the chain The oxygen isn't sterically hindered. Its actually pretty available to be protonated. The carbon however is surrounded by other carbons and hydrogens which increases steric hindrance at that site. Which is actually the only thing that matters since the nucleophile will be attacking that carbon and not the oxygen that presumably already left the molecule as H20. D is correct. Hydride shifts - correct answer are not DIRECT products. direct products= products without rearrangement. If a solution containing the compounds shown in Figure 4, is injected into a gas-liquid chromatograph, the first peak observed in the gc trace is attributable to which compound? A.2-Methyl-2-butanol B.2-Methyl-2-butene C.2-Chloro-2-methylbutane D.2-Bromo-2-methylbutane - correct answer Gas chromatography will elute the LIGHTEST molecular weight FIRST. B is the lightest compound Chirality - correct answer if lowest priority is on a wedge, flip the stereochemistry. if on dash, you gucci In determining which reactant loses the -OH group, which of the following isotopic substitutions would be most useful? A.Replace the acidic H of acetic acid with D. B.Replace the alcoholic H of ethanol with D. C.Replace the carbonyl oxygen of acetic acid with O-18. D.Replace the hydroxyl oxygen of ethanol with O-18. - correct answer D. this would be the oxygen that is added to the product